The present invention relates to a swashplate type compressor for compressing a gas. More specifically, the present invention relates to a housing member for a swashplate type compressor. The housing member defines one or more oil collection grooves that facilitate distribution of a lubricant within the crank chamber of such a compressor.
Swashplate type compressors are frequently used in refrigeration circuits such as those used in automotive applications. These compressors operate through an engagement between one or more pistons and a swashplate. Rotation of the swashplate, which is oriented at an angle to the axis of rotation of a drive shaft, causes the engaged pistons to reciprocate within individual cylinder bores. This reciprocation allows the pistons to compress the refrigerant as part of the mechanical refrigeration process.
There are several points of frictional contact within a swashplate-type compressor. For example, a pair of shoes are typically disposed between each piston and swashplate and swivel within concave pockets as the swashplate rotates. The interface between the shoes and swashplate is an area of sliding contact, giving rise to friction and wear. Also, the drive shaft is typically disposed on a needle or other type of bearing, and rotates while in contact with the bearing. Furthermore, lubrication of the shaft seal is important to compressor functioning. Over time, wear at any of these points of contact can lead to seizure of the compressor, especially in conditions in which lubricant supply is inadequate. This failure mode is one principal limitation on the useful life of a swashplate type compressor.
The present invention provides a swashplate-type compressor having a housing member that defines one or more channels that are adapted to collect and distribute a lubricant within the crank chamber of the compressor. Preferably, the housing member defines a main aperture, an annular groove disposed around the main aperture, and a plurality of oil collection grooves extending outward from the annular groove. Each oil collection groove is in fluid communication with the annular groove, and has a first wall that is perpendicular to the plane of the housing member and a second wall that is angled with respect to the first wall and the plane of the housing member.
The oil collection grooves are preferably angled in position on the housing member, and each may comprise two linear segments joined at an angle or a curvilinear groove. Also, the second wall of each groove can be curvilinear.
The housing member is particularly well-suited for incorporation into a swashplate type compressor having a cylinder block defining a cylinder bore and a crank chamber, a shaft partially disposed within the chamber, a piston reciprocally disposed in the cylinder bore, a swashplate fixedly mounted to the shaft and disposed within the chamber, and shoes which slideably intervene between the piston and the swashplate.